Liquids which are sold in small consignments, such as pharmaceutical products and reagents, have been packed in tubes, bottles, or other similar containers with an equipment, which automatically fills and closes the container and attaches an etiquette to it. On the packaging lines concerned, the liquid to be packed is typically led through a portioner or a part of the portioner, while the portioning space is full of the liquid concerned. Peristaltic pumps and rotating piston pumps, among others, have been used as portioners with liquid consignments of the magnitude of few milliliters.
The patent document U.S. Pat No. 4,987,726 features a certain packaging line of pharmaceutical liquids in accordance with the prior art, where the liquid, driven by the hydrostatic pressure, flows from an upper container to bottles which are preceding on the packaging line.
The above described technique is severely inadequate in the respect that, if the equipment is used in packaging several products, then due to the risk of contamination the portioning spaces and tubes have to be emptied and cleaned thoroughly every time a change is made from one product to the next. These difficult and time consuming manouvers present a serous impediment especially when the consignments are small, typically in the range of 100-5000 packages, and the product repertuare is diverse.